The invention relates to a process, and a device for implementing the process for the production of plastic fiber boards using balls of expanded glass, expanded clay, pumice granules, mica, or a similar material and a foamed organic binder such as epoxy resin, PU phenol resin, or the like, or an inorganic binder, which is mixed with the balls, foamed, and then hardened between two mold plates positioned from each other at a given distance while a matrix is formed.
In a process of this type known to the prior art (DE-OS 37 15 487) the expanded glass ball artificial resin mixture fills the entire space bordered by the level mold plate surfaces, with the exception of small air space between the expanded glass balls. The weight of such plastic fiber boards and the quantity of material needed for their production basically depends on the material compression achieved by pressure applied to the material before hardening. As cores of sandwich elements, plastic fiber boards of this type, in which the cover layers serve as tension elements, are highly stable and have a high load-bearing capacity.